2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)最新文献

{"title":"Random decision forests for automatic brain tumor segmentation on multi-modal MRI images","authors":"Adriano Pinto, Sérgio Pereira, H. Dinis, Carlos A. Silva, D. Rasteiro","doi":"10.1109/ENBENG.2015.7088842","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088842","url":null,"abstract":"Brain tumour segmentation from Magnetic Resonance Imaging (MRI) scans have an important role in the early tumour diagnosis and radiotherapy planning. However, MRI images of the brain contain complex characteristics, such as high diversity in tumour appearance and ambiguous tumour boundaries, even when using multi-sequence MRI images. We propose a fully automatic segmentation algorithm based on a Random Decision Forest, using a k-fold cross-validation approach. The extracted features are the intensity complemented with other appearance and context based features. The post-processing phase has a morphological filter to deal with misclassification errors. Our method is capable of detecting the tumour and segmenting the different tumorous tissues of the glioma achieving competitive results.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116424517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metabolic.Care: Development and characterization of a new thermographic platform for diabetic foot detection","authors":"H. Pereira, Pedro do Mar, C. Correia","doi":"10.1109/ENBENG.2015.7088826","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088826","url":null,"abstract":"Summary form only given. Foot complications due to diabetes - diabetic foot disease - constitute an important economic burden on healthcare systems and impose a loss of quality of life for the patients, leading to limb-threatening (amputation) in most circumstances. Over the last years, several studies have demonstrated that there is a correlation between increased temperature and diabetic foot condition and that temperature augmentation may be detected at a reversible phase of the disease. Conventional non-invasive methods to assess foot temperature include physical palpation or infrared (IR) thermometry. However, the increase in temperature is typically too slight to be detected manually while taking foot temperature with a thermometer is very time consuming and provides only discrete values. The ideal instrument should provide fast temperature readings of the entire foot in one measurement procedure. Although a few technologies are available (liquid crystal thermography, IR cameras, etc.), none has been adopted in clinical practice up till now. This paper proposes a novel thermographic platform for diabetic foot detection based on a thermochromic liquid crystal (TLC) sheet and a modified A3 scanner that acquires images from the TLC sheet. Both elements are enclosed in a metallic and ergonomic structure that allows their physical support. The image is obtained when the patient, in a sitting position, places his feet on the TLC sheet and is subsequently analysed using dedicated image processing algorithms. The significant advantage of this system over the state of the art is the capability to obtain several subsequent images during dynamic changes in skin temperature, making the necessary human intervention minimal. Furthermore, the system is connected to an application hosted on the eVida web platform that allows data uploading, processing and the creation of alarms. The thermographic platform was characterized in a bench test, using two novel Peltier-based calibration systems, and with the feet of a healthy subject. Aspects related to differential thermal resolution of the TLC sheet, contact time between the calibration system/foot with the TLC sheet, the cooling process of the platform and image resolution were tested. The new platform demonstrated a very good performance on the bench and in vivo tests and results showed that it was possible to detect thermal differences between 1o C - 1.6o C (bench tests). Although in vivo studies will be extended to a more significant number of subjects to differentiate between healthy/non-healthy groups, this thermographic platform appears to be a promising and easy to use alternative to detect and monitor diabetic foot condition in a medical environment.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116228221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An ultra-high resolution preclinical positron emission tomography scanner","authors":"P. Martins, A. Blanco, P. Crespo, M. Marques, R. Marques, P. M. Gordo, M. Kajetanowicz, G. Korcyl, L. Lopes, J. Michel, M. Palka, M. Traxler, A. Abrunhosa, M. Couceiro, P. Fonte","doi":"10.1109/ENBENG.2015.7088828","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088828","url":null,"abstract":"Positron Emission Tomography (PET) is a powerful functional imaging technique targeted for in vivo quantification and localization of physiological and pathophysiological functions. The possibility to develop a vast number of diseases in transgenic and knockout mice, and the chance to follow the onset of the diseases and the evolution of the treatment efficacy in an individual basis, made PET the third preferred preclinical imaging technique (20%) in research and development of new drug therapies [1]. Two features are mandatory in a preclinical PET system: a high Full Width at Half Maximum (FWHM) Spatial Resolution (SR), comprised between 0.40 and 0.27 mm for mice, so as to achieve the same level of detail of current state-of-the art PET scanners for humans [2], and a sensitivity as high as possible, to allow to differentiate and quantify a subtle signal in the presence of significant background counts [3]. Commercially available state-of-the-art preclinical PET systems make use of detectors based on segmented inorganic scintillation crystals coupled to photodetectors [2]. To reduce the complexity and cost, light multiplexing is used to decode the position of interaction of annihilation photons [3]. This scheme poses some limitations to the sensitivity and SR attained by preclinical PET systems, due to, among other problems, the difficulty of measuring efficiently the Depth-Of-Interaction [3]. The best reported values for the sensitivity and SR of current commercially available preclinical PET systems, are of, respectively, ~10% and ~1 mm FWHM [2]. Timing Resistive Plate Chambers (RPCs) are gaseous detectors with resistive parallel plate electrodes (made of glass) separated by small (~300 μm thick) and precise amplification gaps filled with an appropriate gas mixture. For the detection of photons, these are first converted into electrons in the resistive plates in an electronic cascade process. Some of the originated electrons will eventually escape to the amplification gap, where they will be accelerated by a uniform electric field, leading to a Townsend avalanche, which induces a current in a set of signal pickup strips. These low cost detectors have an excellent time resolution of 300 ps FWHM for 511 keV photon pairs, an excellent intrinsic SR, the readout being in almost full 3D mode. Recently, we developed a first fully functional prototype of a preclinical RPC-PET scanner for mice, which revealed a SR of 0.4 mm FWHM after image reconstruction by a Maximum Likelihood Expectation Maximization type algorithm. Preliminary tests with mice, preformed at the Institute of Nuclear Sciences Applied to Health (ICNAS - Instituto de Ciências Nucleares Aplicada às Saúde) of the University of Coimbra, shown the capability of the system to clearly identify the very small brain structures of mice, as well as the heart walls. The results obtained thus far are very promising, revealing unprecedented SR.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126525077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization and validation of [13N]-NH3 production for clinical studies of positron emission tomography in the evaluation of myocardial perfusion","authors":"C. Serra, Ângela Neves, A. Abrunhosa, L. Metello","doi":"10.1109/ENBENG.2015.7088887","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088887","url":null,"abstract":"The present work aims to validate the [13N]-NH3 production for human studies of myocardial perfusion using a cyclotron from a Portuguese public institution and an automatic synthesis module. According to specifications of European Pharmacopeia (Ph. Eur.) 8.2., 3 consecutives batches were evaluated for this purpose. Results showed a clear and colorless product and pH values between 4,5 e 8,5. The chemical purity was confirmed by the colorimetric test and the samples were identified as [13N]-NH3, by ionic chromatography, gamma ray spectroscopy and half-life determination. Radiochemical and radionuclidic purity were confirmed, corresponding a minimum of 99% of total radioactivity to [13N] and a percentage of impurities less than 1%, 2 hours after the end of synthesis. Tests for sterility and for presence of bacterial endotoxins were also performed.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125770506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"‘miSimBa’ — A simulator of synthetic time-lapsed microscopy images of bacterial cells","authors":"Leonardo Martins, Jose Fonseca, A. Ribeiro","doi":"10.1109/ENBENG.2015.7088854","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088854","url":null,"abstract":"Escherichia coli is a model organism for the study of multiple biological processes, including gene expression and cellular aging. Recently, these studies started to rely on temporal single cell imaging. To support these efforts, available automated image analysis methods should be improved. One important step is their validation. Ideally, the “ground truth” of the images should be known, which is possible only in synthetic images. To simulate artificial images of E. coli cells, we are developing the `miSimBa' tool (Microscopy Image Simulator of Bacterial Cells). `miSimBa' simulates images that reproduce the spatial and temporal bacterial organization by modelling realistically cell morphology (shape, size and spatial arrangement), cell growth and division, cell motility and some internal functions and intracellular structures, namely, the nucleoid. This tool also incorporates image acquisition parameters that simulate illumination and the primary sources of noise.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126553589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maxwell's equations based 3D model of light scattering in the retina","authors":"M. Santos, A. Araújo, S. Barbeiro, F. Caramelo, A. Correia, Maria Isabel Marques, M. Morgado, L. Pinto, P. Serranho, Rui Bernardes","doi":"10.1109/ENBENG.2015.7088869","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088869","url":null,"abstract":"The goal of this work is to develop a computational model of the human retina and simulate light scattering through its structure aiming to shed light on data obtained by optical coherence tomography in human retinas. Currently, light propagation in scattering media is often described by Mie's solution to Maxwell's equations, which only describes the scattering patterns for homogeneous spheres, thus limiting its application for scatterers of more complex shapes. In this work, we propose a discontinuous Galerkin method combined with a low-storage Runge-Kutta method as an accurate and efficient way to numerically solve the time-dependent Maxwell's equations. In this work, we report on the validation of the proposed methodology by comparison with Mie's solution, a mandatory step before further elaborating the numerical scheme towards the propagation of electromagnetic waves through the human retina.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122253138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prototype for determination of pre-transfusion tests based on image processing techniques","authors":"A. Ferraz, J. Machado, V. Carvalho","doi":"10.1109/ENBENG.2015.7088849","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088849","url":null,"abstract":"This paper presents an innovative prototype to perform pre-transfusion tests especially developed for emergency situations. This prototype is portable and automates the procedure of the plate test. The prototype is based on image processing techniques to analyze the captured images from the performed test. The image processing techniques are able to detect agglutination reactions in the samples and based on the results of occurrence or absence of agglutination the result of the test is given. This paper also presents a user-friendly interface application to be used with the prototype developed. In this study the tests were performed with the prototype for ABO and Rh blood types and the prototype was tested with donor blood samples.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"170 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132773853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simplified multibody model for dynamic loading analysis of the lumbar human spine","authors":"V. Sousa, J. Claro","doi":"10.1109/ENBENG.2015.7088888","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088888","url":null,"abstract":"Evaluation of the loads on spine is very important since it is closely related to the spine biomechanics and its pathologies. In this study, a simplified multibody model of the human skeleton is presented, able to estimate forces and moments acting on the lumbar spine during simple daily activities. The model was validated by comparing the forces and moments in the lumbar spine, measured on two in vivo patients performing frontal and lateral flexion movements. The results show that the model is capable of reproducing the motion as well as to quantify the forces and moments acting on lumbar spine.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114120930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diffusion kurtosis imaging: Monte Carlo simulation of diffusion processes using crowdprocess","authors":"David Naves Sousa, H. Ferreira","doi":"10.1109/ENBENG.2015.7088857","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088857","url":null,"abstract":"Diffusion Kurtosis Imaging quantifies the non-gaussianity of water diffusion. The sensitivity of the diffusion kurtosis model to the microstructural heterogeneity of biological tissues can be studied using Monte-Carlo simulations, which being computationally expensive, can be better applied using parallel computing. To demonstrate the advantages of simulating diffusion processes in distributed computing, in this study, we focused on the correlation between kurtosis of diffusion and three important microstructural changes: intracellular volume fraction, cell radii and cell permeability. A comparison was made between processing in a common laptop CPU, and in CrowdProcess, a new method of parallel computing that uses a browser-powered distributed computing platform. CrowdProcess has proved to be extremely fast compared to the traditional method, bringing the possibility of increasing simulations numerical precision without the time-consuming cost.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125465000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a universal surgical guide to perform low invasive knee surgeries","authors":"M. Marques, J. Belinha, M. Parente, A. A. Fernandes, A. Oliveira, A. Vilaca, J. R. Natal","doi":"10.1109/ENBENG.2015.7088814","DOIUrl":"https://doi.org/10.1109/ENBENG.2015.7088814","url":null,"abstract":"Summary form only given. The human knee, which is a mobile pivotal condylar join that permits flexion, extension and a slight internal and external rotation, is the largest join in the human body. The ligaments of the knee provide stability, limit the knee movement and help to protect the articular capsule. The anterior cruciate ligament (ACL), one of the four main ligaments of the knee, is extremely important in the stabilization of the knee when turning or planting. The rupture of the ACL is one of the most common knee injuries, where the surgical procedure for its reconstruction is done through arthroscopy, a low-invasive surgery performed using a small camera, an arthroscope. In case of injury an orthopedist surgeon evaluates the ligament damage, and thus he chooses the patient bone site to drill in order to insert a previously harvested tissue that will substitute the damaged ACL. The success of this surgical procedure depends mainly on the surgeon ability and skill to drill accurately the holes in the bone, since non-anatomic bone tunnel misplacement has been reported as the most common cause of ACL reconstruction failure. With this, and, using a patient specific instrumentation (PSI) systems, that is being developed as a replacement for traditional instrumentation in total knee arthroplasty (TKA), this study intends to adapt this in-developing technology to ACL repair surgery. Using the PSI concept to precisely locate the femoral tunnel location during the procedure, a guide item will be generated using 3D anatomic information gathered from magnetic resonance imaging (MRI) and/or computed tomography (CT) imagery. In the end, the present proposal aims to deliver a prototype for a universal surgical guide, capable to assist low-invasive knee surgeries for the ACL reconstruction. Thus, in the course of the reconstruction surgery, this universal surgical guide will permit to mark the exact location of the bone drill, as planned in the pré-surgical study.","PeriodicalId":285567,"journal":{"name":"2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133963191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}